CJC-1295 with DAC

What CJC-1295 with DAC is

CJC-1295 with DAC is a lab-made peptide built to keep growth hormone (GH) release going for a long time. It has been tested in rats, in mice and in small early-phase studies of healthy adults. As of 2026 it is still an experimental research compound. It has not gone through phase 2 or phase 3 testing, and the FDA, the EMA and the MHRA have not approved it. Everything in this guide comes from peer-reviewed papers.

A peptide is a short chain of amino acids, the building blocks of protein. This one is an analog, meaning a changed copy, of GHRH (growth hormone-releasing hormone). GHRH is the body’s own signal that tells the pituitary gland, a gland at the base of the brain, to let out GH.

The copy is based on a 29-amino-acid piece of GHRH, usually written GRF(1-29). GRF(1-29) is the front end of the full hormone. In 1984, scientists isolated the hormone from human hypothalamus tissue and worked out its sequence. It matched a form found shortly before in a human pancreatic tumor [1]. A whole family of research analogs grew from this parent sequence. Sermorelin is one. The shorter-acting “No DAC” version of CJC-1295 is another. They all act on the same GHRH receptor in the pituitary. A receptor is a spot on a cell where a signal attaches.

What sets this compound apart from its parent is the DAC, or Drug Affinity Complex. It is a chemical add-on. Once the peptide is injected, the DAC binds it to albumin, a protein that travels in blood serum. The bond is covalent, and the binding is described as permanent [8], [10].

The reason for the add-on is speed of loss. Natural GRF(1-29) is gone from the blood within minutes. Scientists changed it for one purpose, to keep it in plasma longer. Animal and lab studies describe the result as a molecule that keeps acting on the GHRH receptor over a much longer window than the plain peptide does [8].

How much research there is

Animal and lab studies plus a few small human studies, mostly from the company that made the compound.

Question	Answer
Stage of evidence	Animal and lab drug studies, and small human studies at an early phase. Nothing from phase 2 or 3 is in print
What was tested	Rodents and receptor-binding tests. Small early human studies of single and repeated doses. Supporting work on blood markers and on the DAC chemistry
Who was studied	Small groups of healthy adult volunteers. Normal rodents and mice with the GHRH gene knocked out
Checked by other labs	Separate groups using different methods all reported a switched-on GH/IGF-1 axis. The methods were receptor activation, growth recovery, dose-response and marker panels [8], [12], [9], [14]
Who paid for it	The discovery work and early human studies came from research sponsored by the compound’s own developer. Outside academic marker research has added to this base but not replaced it
Longest study	Several weeks of repeated doses, in the longest early human study found
Approval	Experimental. None from the FDA, EMA or MHRA
Do the results agree	Yes. Animal and early human work both report higher GH and IGF-1 through the GHRH receptor. Small sample sizes limit what can be said about the exact size of the effect

How it might work

The design has two parts that can be looked at apart. One is a peptide sequence that attaches to the GHRH receptor. The other is a tag that bonds to albumin so the sequence stays in the blood longer.

Switching on the GHRH receptor

The peptide chain of CJC-1295 is built to turn on the GHRH receptor. This is a G-protein-coupled receptor, a common type of cell switch. It sits on somatotrophs, the pituitary cells that make GH.

Scientists had mapped this receptor system long before CJC-1295 existed. Early hormone research showed that it drives both the making of GH and its release in pulses from the front of the pituitary [2].

GH released this way then prompts the liver and outlying tissues to make IGF-1, or insulin-like growth factor 1. This chain from GH to IGF-1 has been studied at length in research on GH biology and on aging [3].

There is a second, separate route to GH release. It runs through the ghrelin receptor, also called the growth hormone secretagogue receptor (GHS-R). Growth hormone-releasing peptides (GHRPs) such as ipamorelin use that route [4]. It was first mapped after ghrelin, a hormone the body makes, was found to be the receptor’s natural partner [5]. Because the two routes differ, the two classes of compound are often studied together as a pair.

The Drug Affinity Complex

The DAC is a reactive linker based on a chemical group called maleimide. It is fixed to the GHRH(1-29) chain. After injection, the linker is built to bond covalently to Cys34 on albumin in the blood, at that amino acid’s free thiol group [8].

Tying a peptide to albumin is a known way to make it last longer in plasma. There are two reasons. The joined pair is too big for the kidneys to filter out quickly. It also takes on albumin’s own long life in the blood. Reviews of albumin as a drug carrier cover this general rule in depth [13].

The team behind CJC-1295 later used the same DAC chemistry on a peptide of an unrelated class. The result was CJC-1131, a GLP-1 receptor agonist joined to a DAC. An agonist is a compound that switches a receptor on. Scientists used CJC-1131 to learn more about what the albumin-binding tag does, apart from whatever peptide it carries [6].

Longer half-life, and whether pulses survive

Time in the blood is the main thing that separates the DAC form from the No DAC version. Half-life is the time it takes for half of a compound to leave the blood. Animal and early human studies describe the DAC form as active in the blood for days. Natural GRF(1-29) has a half-life counted in minutes. An equally short span is reported for related GHRH(1-29) analogs with no such add-on, such as sermorelin [11].

That raises another question. The pituitary normally releases GH in pulses. Does longer stimulation of the GHRH receptor wipe out that pattern and leave a flat, steady signal?

A human study looked at this directly. GH kept coming in pulses for the whole time people were exposed to CJC-1295 without a break. Steady release did not take over [10]. Scientists see this as important for how the compound works. In GH research, exposure in pulses is linked to different signals further down the chain than constant exposure is.

What the studies found

These results come from animal and lab studies and from small human studies at an early phase. When this guide was last reviewed, no data from phase 2 or 3 had been published for the compound.

In animals and tissue

• Rat pituitary tissue. The paper that first described CJC-1295 as a GRF analog joined to a DAC tested hGRF(1-29) bound to albumin. These bioconjugates turned on the GRF receptor in tissue from the front of the rat pituitary. So the DAC add-on did not wipe out the receptor binding that the natural peptide has [8].
• Knockout mice. One study used mice with the GHRH gene knocked out, so they made no GHRH of their own. Their GHRH receptors still worked. CJC-1295 given once a day brought their body weight and length to normal. This showed that the analog can stand in for the missing GHRH [12].

Early studies in people

• GH and IGF-1. An early-phase study gave healthy adults CJC-1295 under the skin, as single doses and as repeated doses. Release of both GH and IGF-1 stayed raised for a long time, and more so at higher doses. After a single dose, GH stayed raised for 6 days or more and IGF-1 for 9 to 11 days. The half-life was 5.8 to 8.1 days. After repeated doses, IGF-1 stayed above baseline for up to 28 days [9].
• Pulses. A related analysis from the same human research project looked at how GH release was patterned under constant CJC-1295 exposure. GH still came in pulses. It was not replaced by a steady, pulse-free output [10].

Blood markers of the GH/IGF-1 axis

• A marker study in normal adults found that CJC-1295 switched on a set of serum proteins that sit downstream of GH and IGF-1. This is separate molecular evidence. It fits lasting activation of the GHRH pathway, and it adds to the GH and IGF-1 readings in the main drug studies [14].

Evidence from the DAC platform

• The DAC chemistry that joins a peptide to albumin was also used on CJC-1131, a GLP-1 receptor agonist from an unrelated class. Studies of how the body handles that separate compound add independent support. They show the long-lasting behavior comes from the DAC tag, whichever peptide it carries [6], [7].
• Wider drug chemistry research treats albumin as a carrier for delivering drugs. It places the DAC method inside a larger, well-studied group of albumin-joining methods. These are used to give small molecules and short-lived peptides a longer stay in the blood [13].

Safety

What research has seen

• One review covered the wide class of growth hormone secretagogues, taking in GHRH analogs such as CJC-1295 as well as GHRP compounds. Across the class, the tolerability findings described most often were reactions where the needle went in and short-lived effects tied to stimulating the GH system [17].
• Clinical practice guidance on checking GH and IGF-1 in adults sets out accepted ways to track GH activity. It stresses that standard measurement matters when reading results for research compounds that raise GH and IGF-1 [15].
• The animal and early human studies found for this guide did not report any safety signal that was unexpected or unusual. What they saw was in line with the known effects of keeping the GHRH receptor switched on [9].

What is not known

• Nothing from a phase 2 or 3 trial is in print. The longest early human study ran for several weeks. Safety beyond that span has not been shown in peer-reviewed papers.
• Safety and benefit have not been shown outside small groups of healthy adults in early studies. That leaves out older adults, teenagers, pregnancy, and people with poor liver or kidney function.
• No formal drug interaction study of CJC-1295 with DAC itself turned up in the papers read for this guide.
• The long-term results of steady, DAC-extended stimulation of the GHRH receptor are still an open question. This differs from the on-and-off stimulation studied with No DAC analogs.
• Few results have been repeated by groups not sponsored by the developer, as the research table above notes.

Legal status in the US

• Not FDA approved. The compound has no approval from the FDA for any use. The same is true of the EMA in Europe and the MHRA in the UK.
• Banned in sport. It is a GHRH analog. That class falls under S2 on the World Anti-Doping Agency (WADA) Prohibited List, which covers growth hormone secretagogues, GHRH analogs, peptides that release GH, and related substances. It is banned at all times, in competition and out of it. Anti-doping papers have singled out the detection of GHRH analogs as a busy field in doping-control science [16].
• Research use. It is supplied for laboratory research use only.

Limits of the research

1. No finished later-phase trial. Nobody has completed a phase 2 or 3 study. Every result here is from animal and lab work or small early human studies. Later trials, if anyone runs them, may report a different effect size and safety record.
2. Few people studied. The published human studies found for this guide used small groups of healthy adult volunteers. That limits how exact the reported effect sizes can be.
3. Discovery work paid for by the developer. The main receptor findings and the early human drug data came out of research sponsored by the developer. Independent academic repeats are limited to add-on marker analyses.
4. Short study length. The longest published treatment period is counted in weeks. It is not months or years. Longer-term effects have not yet been described in peer-reviewed papers.
5. No long-term data specific to DAC. Most of the detailed evidence on how the DAC albumin-binding platform moves through the body comes from CJC-1131. That is a related but separate DAC compound, not CJC-1295.
6. Narrow range of subjects. Research so far has covered rodent models and healthy adult volunteers. The results should not be stretched to other groups or settings.

CJC-1295 with DAC raised GH and IGF-1 for days in small early studies. No larger trial has tested it.

References

Selected peer-reviewed references, each verified against the CrossRef API before inclusion. Ordered by date of publication.

1. Ling N, Esch F, Böhlen P, Brazeau P, et al. (1984). Isolation, primary structure, and synthesis of human hypothalamic somatocrinin: growth hormone-releasing factor. Proceedings of the National Academy of Sciences, 81(14), 4302–4306. DOI: 10.1073/pnas.81.14.4302
2. Frohman LA, Jansson JO (1986). Growth Hormone-Releasing Hormone. Endocrine Reviews, 7(3), 223–253. DOI: 10.1210/edrv-7-3-223
3. Corpas E, Harman SM, Blackman MR (1993). Human Growth Hormone and Human Aging. Endocrine Reviews, 14(1), 20–39. DOI: 10.1210/edrv-14-1-20
4. Raun K, Hansen BS, Johansen NL, Thøgersen H, et al. (1998). Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology, 139(5), 552–561. DOI: 10.1530/eje.0.1390552
5. Kojima M, Hosoda H, Date Y, Nakazato M, et al. (1999). Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature, 402(6762), 656–660. DOI: 10.1038/45230
6. Léger R, Thibaudeau K, Robitaille M, Quraishi O, et al. (2004). Identification of CJC-1131-albumin bioconjugate as a stable and bioactive GLP-1(7–36) analog. Bioorganic & Medicinal Chemistry Letters, 14(17), 4395–4398. DOI: 10.1016/j.bmcl.2004.06.066
7. van Vliet A, Tiessen R, Kruizinga M, Dreyfus J, et al. (2005). Pharmacokinetics and tolerability of a novel long acting glucagon-like-peptide-1 analog CJC-1131 [conference abstract]. Clinical Pharmacology & Therapeutics, 77(2), P56. DOI: 10.1016/j.clpt.2004.12.102
8. Jetté L, Léger R, Thibaudeau K, Benquet C, et al. (2005). Human Growth Hormone-Releasing Factor (hGRF)1–29-Albumin Bioconjugates Activate the GRF Receptor on the Anterior Pituitary in Rats: Identification of CJC-1295 as a Long-Lasting GRF Analog. Endocrinology, 146(7), 3052–3058. DOI: 10.1210/en.2004-1286
9. Teichman SL, Neale A, Lawrence B, Gagnon C, et al. (2006). Prolonged Stimulation of Growth Hormone (GH) and Insulin-Like Growth Factor I Secretion by CJC-1295, a Long-Acting Analog of GH-Releasing Hormone, in Healthy Adults. The Journal of Clinical Endocrinology & Metabolism, 91(3), 799–805. DOI: 10.1210/jc.2005-1536
10. Ionescu M, Frohman LA (2006). Pulsatile Secretion of Growth Hormone (GH) Persists during Continuous Stimulation by CJC-1295, a Long-Acting GH-Releasing Hormone Analog. The Journal of Clinical Endocrinology & Metabolism, 91(12), 4792–4797. DOI: 10.1210/jc.2006-1702
11. Walker RF (2006). Sermorelin: A better approach to management of adult-onset growth hormone insufficiency? Clinical Interventions in Aging, 1(4), 307–308. DOI: 10.2147/ciia.2006.1.4.307
12. Alba M, Fintini D, Sagazio A, Lawrence B, et al. (2006). Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. American Journal of Physiology-Endocrinology and Metabolism, 291(6), E1290–E1294. DOI: 10.1152/ajpendo.00201.2006
13. Kratz F (2008). Albumin as a drug carrier: Design of prodrugs, drug conjugates and nanoparticles. Journal of Controlled Release, 132(3), 171–183. DOI: 10.1016/j.jconrel.2008.05.010
14. Sackmann-Sala L, Ding J, Frohman LA, Kopchick JJ (2009). Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog, results in serum protein profile changes in normal adult subjects. Growth Hormone & IGF Research, 19(6), 471–477. DOI: 10.1016/j.ghir.2009.03.001
15. Molitch ME, Clemmons DR, Malozowski S, Merriam GR, et al. (2011). Evaluation and Treatment of Adult Growth Hormone Deficiency: An Endocrine Society Clinical Practice Guideline. The Journal of Clinical Endocrinology & Metabolism, 96(6), 1587–1609. DOI: 10.1210/jc.2011-0179
16. Baumann GP (2012). Growth Hormone Doping in Sports: A Critical Review of Use and Detection Strategies. Endocrine Reviews, 33(2), 155–186. DOI: 10.1210/er.2011-1035
17. Sigalos JT, Pastuszak AW (2018). The Safety and Efficacy of Growth Hormone Secretagogues. Sexual Medicine Reviews, 6(1), 45–53. DOI: 10.1016/j.sxmr.2017.02.004